Process for the preparation of dispersions

A process for the preparation of a dispersion which comprises feeding an aqueous phase and a solvent phase which comprises a solution of an active substance or composition selected from the group consisting of a fat-soluble vitamin, a pharmaceutical, a carotenoid, and a polyunsaturated fatty acid in dimethylether or in a C4-hydrocarbon or mixtures thereof into a mixing chamber, wherein at least one of the solution or the aqueous phase comprises a carrier, decompressing the mixture and separating the dispersion from gaseous solvent, wherein

• (a) the active substance or composition is dispersed in dimethylether or in a C4-hydrocarbon or mixtures thereof, heated in a heat exchanger for about 5 to 10 seconds, and fed into the mixing chamber by a high pressure pump in such a manner that temperature and pressure are close to or exceed the critical constants of the solvent;
• (b) the aqueous phase comprises a carrier selected from the group consisting of bovine gelatin, swine gelatin, fish gelatin, gum acacia, modified food starches, cellulose derivatives, pectins, and ligninsulfonates, and is fed into the mixing chamber at a pressure and temperature sufficient to maintain super- or nearcritical conditions;
• (c) the said two phases are mixed in the mixing chamber under turbulent conditions to produce a pre-emulsion;
• and
• (d) the pre-emulsion is decompressed through an aperture, which has a diameter of 0.05 mm to about 1.0 mm and then passes through a residence zone to produce the dispersion which is a finely-dispersed aqueous, solvent-free suspension or emulsion.